1. FIELD OF THE INVENTION
This invention relates to oil soluble dispersant additives useful in fuel and lubricating oil compositions, including concentrates containing said additives, and methods for their manufacture and use. The dispersant additives are poly (C.sub.5 -C.sub.9 lactone) adducts of amine neutralized dicarboxylic acids, anhydrides, esters, etc., which have been substituted with a high molecular weight hydrocarbon group and then reacted with a polyol or certain amino alcohols, and then with the C.sub.5 -C.sub.9 lactone. The high molecular weight hydrocarbon group has a number average molecular weight (M.sub.n) of about 300 to about 10000. The additives will have a ratio (functionality of about 0.70 to about 2.0 dicarboxylic acid producing moieties for each equivalent weight of the high molecular weight hydrocarbon therein.
2. PRIOR ART
Polyalkylene substituted C.sub.4 -C.sub.10 dicarboxylic acid and anhydride adducts with polyols and polyamines are well known lubricating additives. These agents act to keep sludge and varnish dispersed in engine oils and have been very successful commercially.
It is also known that polymers of 6 to 10 membered lactones such as valerolactone or E-caprolactone can be prepared by reacting the lactone monomer with a hydoxyl or amine initiator. When reacting E-caprolactone, for example, the polymerization reaction may be illustrated by the following equations: ##STR1##
The reactions are known to be catalyzed by various esterification catalysts such as stannous octanoate, and a variety of different molecular weight products are feasible depending upon the ratio of lactone to initiator. Molecular weights on the order of from a few hundred up to about 5,000 are reproducably achievable.
Caprolactone can also be polymerized to a very high molecular weight, e.g., on the order of 100,000 or more. Typically such high molecular weight polymers do not employ initiators and preservation of functionality is not a requirement.
It is also known to react a lactone such as E-caprolactone with a polyol to form polyesters having terminal hydroxyl groups which are useful as plasticizers.
It has now been found that improved oil soluble dispersant additives, useful in fuel and lubricating oil compositions, including concentrates containing the additives, can be prepared by polymerizing a 6 to 10 membered lactone using as the initiator those lactone reactive hydroxyl functions contained within a known class of oil soluble dispersants, namely: dicarboxylic acids, anhydrides, esters, etc. that have been substituted with a high molecular weight hydrocarbon group and esterified with a polyol. A typical example of one such initiator is a polyalkylene succinic anhydridepentaerythritol adduct wherein the polyalkylene moiety has a number average molecular weight of about 300 to about 10,000 and wherein the ratio (functionality) of succinic acid producing moieties to each equivalent weight of the polyalkylene moiety is from about 0.70 to about 2.0.
While there are a number of prior art disclosures relating to esterfied polyalkenyl succinic acid or anhydride type dispersants, and to lactone polymerization reactions, in general, little or no prior art of direct pertinence appears to have surfaced in regard to the present dispersants. Exemplary of the patent literature which relates to lactone polymerization processes and/or to oil soluble dispersant additives are the following U.S. Patents: U.S. Pat. No. 4,362,635 discloses synthetic ester oils which are esterification products of monoalcohols and dicarboxylic acids or of polyhydric alcohols and monocarboxylic acids respectively, containing 5 to 45% by weight of units of hydroxycarboxylic acids obtained from aliphatic alcohols, aliphatic, cycloaliphatic or aromatic carboxylic acids, and lactones of aliphatic C.sub.5 -C.sub.12 hydrocarboxylic acids. The synthetic ester oils are suitable for the preparation of lubricants and lubricant compositions.
U.S. Pat. No. 2,890,208 discloses a process for polymerizing lactones to form lactone polyesters that are useful as plasticizers.
U.S. Pat. No. 3,950,341 relates to oil soluble detergent dispersants which are prepared by reacting a polyalkenyl succinic acid or its anhydride with a hindered alcohol such as pentaerythritol, and then with an amine.
U.S. Pat. No. 3,708,522 relates to lubricating oil additives which are oil soluble, mono- or polycarboxylic acid esters which are post-treated with mono-or polycarboxylic acylating agents. Esters of polyisobutenyl-substitued succinic anhydride and pentaerythritol post-treated with maleic anhdride exemplify the process and compositions disclosed in this patent.
U.S. Pat. No. 4,062,786 and its continuation-in-part (U.S. Pat. No. 4,292,184) disclose lactone oxazoline reaction products of hydrocarbon substituted lactone carboxylic acids such as polybutyl lactone carboxylic acid, with a 2,2-disubstituted-2-amino-1-alkanol such as tris-(hydroxymethyl)-amino-methane (THAM). The reaction products and their derivatives are disclosed as being useful additives in oleaginous compositions such as sludge dispersants for lubricating oil.
U.S. Pat. No. 4,169,836 discloses reacting hydrocarbon substituted dicarboxylic acids, esters, or anhydrides, for example, octadecenylsuccinic anhydride and polyisobutenyl succinic anhydride with 2,2-disubstituted-2-amino-1-alkanols, for example, THAM, to form oxazoline products which are useful as additives in oleaginous compositions, such as sludge dispersants for lubricating oil.
U.S. Pat. No. 4,017,406 discloses carboxylate half esters of 1-aza-3,7-dioxabicyclo [3.3.0] oct-5-yl methyl alcohol which are the reaction products of long chain dicarboxylic anhydrides, such as polyisobutenyl succinic anhydride, and aldehyde/THAM adducts. The esters are useful as lubricating oil additives, friction modifiers and the like, depending upon the molecular weight. The disclosure of this patent is expressly incorporated herein by reference.
U.S. Pat. No. 4,102,798 relates to oil soluble oxazoline reation products of polyisobutenyl succinic anhydride and THAM which are useful additives in oleaginous compositions, such as sludge dispersants for lubricating oil or gasoline.
U.S. Pat. Nos. 4,113,639 and 4,116,876 disclose an example of alkenyl succinic anhydride having a molecular weight of the alkenyl group of 1,300 and a Saponification Number of 103 (about 1.3 succinic anhydride units per hydrocarbon moledule). This alkenyl succinic anhydride may be reacted with polyamine and then boric acid (U.S. Pat. No. 4,113,639), or may be reacted with an amino alcohol to form an oxazoline (4,116,876) which is then borated by reaction with boric acid.
U.S. Pat. No. 3,219,666 discloses as dispersing agents in lubricants, derivatives of polyalkenyl succinic acids and nitrogen compounds, including polyamines. The preferred molecular weight of the polyalkenyl moieties is 750-5,000.
U.S. Pat. No. 4,234,435 discloses as oil additives, polyalkylene substituted dicarboxylic acids derived from polyalkylenes having a M.sub.n of 1300 to 5,000 and containing at least 1.3 dicarboxylic acid groups per polyalkylene. In Example 34 of that patent, a polyisobutene-substituted succinic acylating agent is reacted with caprolactam in the presence of mineral oil and sodium hydroxide.
U.S. Pat. No. 3,381,022 relates to ester derivatives of substantially saturated polymerized olefin-substituted succinic acid wherein the polymerized olefin substituent contains at least about 50 aliphatic carbon atoms and has a molecular weight of about 700 to 5,000. The esters include the acidic esters, diesters, and metal salt esters wherein the ester moiety is derived from monohydric and polyhydric alcohols, phenols and naphthols. The ester derivatives are useful as additives in lubricating compositions, fuels, hydrocarbon oils and power transmission fluids. A related application, i.e., U.S. Pat. No. 3,522,179, relates to lubricating compositions comprising a major amount of a lubricating oil and a minor proportion of an ester derivative of a hydrocarbon-substituted succinic acid sufficient to improve the detergency of the lubricating composition. The ester derivatives are similar to those described in U.S. Pat. No. 3,381,022 and contain at least about 50 aliphatic carbon atoms. The hydrocarbon substituent may be derived from a polymerized lower monoolefin having a molecular weight of from about 700 to about 5,000.
U.S. Pat. No. 4,502,970 discloses lubricating oil compositions useful in both gasoline engines and diesel engines. The compositions contain a polyisobutenyl succinicimide as a supplemental dispersant-detergent in combination with another conventional dispersant. The polyisobutenyl group has a M.sub.n of about 700-5,000.
U.S. Pat. No. 4,379,914 and its continuation-in-part (U.S. Pat. No. 4,463,168) disclose the preparation of polycaprolactone polymers by reacting E-caprolactone with a diamine wherein one of the amine groups of the diamine is a tertiary amine and the other is a primary or secondary amine. The polycaprolactone polymers are disclosed as being useful for neutralizing certain sulfonic acid-containing polymers to form amine-neutralized, sulfonated derivatives which can be combined with an alkyl benzene sulfonic acid to give a surfactant which contains ester groups, hydroxyl groups and amine-neutralized sulfonate groups.
U.S. Pat. No. 3.169,945 discloses the preparation of lactone polyesters which are useful as plasticizers and as intermediates for preparing elastomers and foams. The polyesters can be prepared by reacting a lactone such a E-caprolactone with an initiator such as an alcohol, amine or amino alcohol.
All of the above discussed patents are expressly incorporated herein by reference in their entirety.
Additional exemplary prior art disclosures, which are expressly incorporated herein by reference in their entirety are U.S. Pat. Nos. 2,767,144; 3,087,936; 3,131,150; 3,154,560; 3,172,892; 3,198,736; 3,202,678; 3,215,707; 3,231,587; 3,325,484; 3,269,946; 3,272,743; 3,272,746; 3,278,550; 3,284,409; 3,284,417; 3,288,714; 3,361,673; 3,367,895; 3,379,693; 3,390,086; 3,401,118; 3,403,102; 3,455,827; 3,562,159; 3,576,743; 3,632,510; 3,684,771; 3,792,061; 3,799,877; 3,836,470; 3,836,471; 3,838,050; 3,838,052; 3,879,308; 3,912,764; 3,927,041; 4,110,349; 4,116,875; 4,123,373; 4,151,173; 4,167,073; 4,263,153; 4,486,326; 4,517,104; 4,532,058; 4,536,547 and Reissue 26,330.